The present invention relates to liquid samplers.
Apparatus for sampling liquids are well known. They are frequently provided to sample liquids in, for example, a pipeline.
Although the invention is not restricted to the following use, samplers for bunker fuel oil are particularly difficult to design. The reason for this is that bunker fuel for ships tends to be of very low quality and generally comprises the residue of the oil after the more usable parts have been removed mixed with diesel fuel. The fuel oil tends to be very waxy and, indeed, unless it is kept hot may solidify.
It is desirable to sample bunker fuel as it is being loaded into a ship because it's constituents can vary and it is common to sample such bunker fuel so as to determine it's constituents for future analysis. It is common practice for three samples to be kept in separate containers, one by the ship owner, one by the fuel supplier, and one for retention for later analysis/arbitration if so required.
A known arrangement of sampler comprises a valve mechanism which is rotated, rotation of the valve mechanism selectivety pas, sing a sample of liquid within the pipeline to three sampling jars, the rotation of the valve being carried out by a drive system driven by means of a propeller within the pipeline so that the propeller rotates in accordance with the flow of bunker fuel and the amount of bunker fuel collected, therefore, is in some way dependent upon the amount of bunker fuel passed along the pipeline. Such an arrangement is useful particularly in that it does not require an outside power supply (which is highly desirable in the somewhat explosive environment that the sampler operates).
However there are some difficulties, particularly caused by the fact that the bunker fuel tends to be waxy and solidify.